This invention is directed to an apparatus for automatically, rapidly, and accurately measuring an amount of gun powder being dispensed, so as to improve the convenience and accuracy of hand-loading cartridges. There are devices which provide rapid dispensing or alternatively accurate dispensing, but none presently known which provide both rapid as well as accurate dispensing of gun powder. There is one system which automatically dispenses gun powder to a scale described in U.S. Pat. No. 2,833,506 but its accuracy and speed depend upon mechanically constructed devices having mechanical friction in the sensor mechanism which can cause uncertainties in the dispensing operation. That patent describes a feeder system constructed with a chute to vary the trajectory of a powder as it is being dispensed to limit the amount of powder distributed to a tray mounted on a scale. The mechanical tilting is electrically controlled to slow the flow through a notch in the chutes which limits the amount of gun powder that falls on a scale. The need to control this tilting action is what gives rise to the uncertainty.
Methods for rapid dispensing are often based on a mechanical loader that has an adjustable volume for selection of the desired load. These types of mechanical loaders typically have a movable piston in a cylinder to choose the volume of the desired load. The loaded powder is either translated to a dump opening or rotated on a master cylinder to a dump opening. Since most gun powder in not spherical in shape, but instead cylindrical, it is not possible to obtain extremely accurate or reproducible loads by volume measurements alone. Their accuracies can vary appreciably with the size of the grain.
There is a method of measuring an extremely accurate amount of gun powder but it is very slow and tedious. This method involves the use of a precision scale which is the most accurate method of measuring precise amounts of gun powder known in the art. However, this method requires appreciable time and patience to place precise amounts of powder onto the weighing tray. Because this method is so tedious, most operators will use the scale only for an occasional check of the accuracy and reproducibility of their more rapid mechanical loaders. A reproducibility of .+-.0.1 grains is possible with most gun powder precision scales, used by a careful operator. The reproducibility, however, is limitied by the friction of the balance pivot points for a balance scale and the ability of the operator to accurately judge when the precise level mark of the scale is reached. Direct reading scales do not rely on an operator's judgement, but these are considerably more expensive than precision balance scales and they still require a tedious procedure to place an accurate quantity of powder on the scale.
Accurate measurements of gun powder within .+-.0.1 grains are necessary if the shooter's aim is to be accurate. Also, if a shooter wants to load his shells with the maximum charge that his gun can safely withstand it is vital that the measurement of the powder be controlled to at least .+-.0.1 grains to prevent overloading a cartridge shell, which could possibly damage the gun or even injure the shooter.
It is therefore one object of the present invention to provide a powder dispensing apparatus which can rapidly and accurately dispense precise amounts of powder.
Yet another object of the present invention is to provide a powder dispensing apparatus which can measure and dispense a precise amount of gun powder using any type of scale or it can be built into a specially constructed scale.
Still another object of the present invention is to provide a powder dispensing apparatus which utilizes one or more rotatable barrels to convey powder to a scale.
Yet another ojbect of the present invention is to provide a powder dispensing apparatus for measuring precise amounts of gun powder which utilizes optical-electronic sensing means adaptable to any scale that has a beam or deflectable structure, with no inherent mechanical friction.